Splitting DidSwap in cc::SwapPromise into WillSwap and DidSwap

cc/trees/layer_tree_impl.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 351 matching lines @@
   // on the active tree if a new tree is activated.
   void QueuePinnedSwapPromise(std::unique_ptr<SwapPromise> swap_promise);
 
   // Takes ownership of |new_swap_promises|. Existing swap promises in
   // |swap_promise_list_| are cancelled (SWAP_FAILS).
   void PassSwapPromises(
       std::vector<std::unique_ptr<SwapPromise>> new_swap_promises);
   void AppendSwapPromises(
       std::vector<std::unique_ptr<SwapPromise>> new_swap_promises);
   void FinishSwapPromises(CompositorFrameMetadata* metadata);
+  void ClearSwapPromises();
   void BreakSwapPromises(SwapPromise::DidNotSwapReason reason);
 
   void DidModifyTilePriorities();
 
   ResourceId ResourceIdForUIResource(UIResourceId uid) const;
   void ProcessUIResourceRequestQueue();
 
   bool IsUIResourceOpaque(UIResourceId uid) const;
 
   void RegisterPictureLayerImpl(PictureLayerImpl* layer);
@@ skipping 179 matching lines @@
 
   std::unique_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_